Monitoring switch position (prototype)

[faraway]

Switches may be equipped with a "Circuit Controller" such as U-5 or SC-100 to detect the switch blade position and close or open electric contacts. There are may different uses for those devices attached to the switch.

I have a specific question about "the other" equipment involved if a circuit controller is used to signal the position of a hand thrown switch in the mainline to the dispatcher.

The circuit controller is mounted to the switch. What else is installed at or close by the switch to transmit the information to the dispatcher far away? 

I guess there is a box with a radio transmitter, an antenna and may be even a batterie pack as backup.

 

Can you point me to photos of that equipment (radio transmitter, antenna etc.)? 

 

I do not ask for photos of the circuit controllers. I found them with tons of photos and information (e.g. http://www.raildev.com/sc100.html) and plan to install them on two switches but I can not find a link to the local equipment triggered to send the information to the remote dispatcher.

[7j43k]

It seems to me that such a device would only be used on trackage that is signaled.  Signals are hardwired.  This device would likely tie into the signal circuit wiring that was near the track switch.  There would likely be a pad mounted electrical box for the connections.  There might also be relays inside, and then there would likely be a battery box nearby.  These tend to be underground.

Assuming all this is true, there would be no radio equipment.  There would be the electrical box and probably a battery box.

 

Something like this:

 

The above is probably a bit "grander" than what would be used for a simple switch indicator, but it generally illustrates the idea.  Note the pipes coming out of the bottom of the box.

The battery box is in the foreground.

 

Here is a picture of an installation that is similar to what you are describing (at my favorite railroad location--Lyle, WA):

 

 

You can see the tall galvanized metal box.  I believe the battery box is semi-hidden just behind.  The trackage with the train is signaled.  The track coming towards the camera on the right is not.  There is a switch position sensor and also an electric lock.  I have seen maintenance crews travel on the right track, and stop just "below" us.  A guy walks over to the switch.  He talks to the dispatcher (by radio, I think that I recall).  The dispatcher unlocks the switch.  The guy throws the switch.  Etc.

Anyway, whenever that switch is thrown to the siding, the signal system must know that.  Hence, there must be a position sensor.

It is not really a controller.  It is a position sensor.  

 

 

Ed

[faraway]

Thanks a lot for taking the time to post that extensive answer.

[rrinker]

 There definitely are radio versions, not all of it is hard wired. There may be a more modern box holding the equipment, or if there was an old one there, the old big relays are removed and modern solid state circuits installed, along with SLA batteries (the old battery celler nearby that USED to be the power source is usually empty). AC is supplied from a nearby pole, the batteries are just for backup. If a radio installation, there'd be an antenna on top of the box. A hard wired installation would have a cable coming out and going to the pole line.

                                     --Randy

 

[7j43k]

rrinker

 There definitely are radio versions, not all of it is hard wired. There may be a more modern box holding the equipment, or if there was an old one there, the old big relays are removed and modern solid state circuits installed, along with SLA batteries (the old battery celler nearby that USED to be the power source is usually empty). AC is supplied from a nearby pole, the batteries are just for backup. If a radio installation, there'd be an antenna on top of the box. A hard wired installation would have a cable coming out and going to the pole line.

                                     --Randy

 

 

 

Could you supply an example of the radio version, please?

It would be most useful for the OP.

 

Ed

[dehusman]

faraway

The circuit controller is mounted to the switch. What else is installed at or close by the switch to transmit the information to the dispatcher far away? I guess there is a box with a radio transmitter, an antenna and may be even a batterie pack as backup.

No not really. 

Assuming you are talking about a hand throw circuit in ABS territory, there is no indication back to the dispatcher.  All it does is cause the signals in the field to display a restrictive signal.  The switch indicator is wired into the signal circuits. 

Assuming you are talking about a hand throw circuit in CTC territory, there is no indication back to the dispatcher.  All it does is cause a track occupancy indication (looks the same as a train sitting on the tracks or broken rail ) and the signals in the field to display a restrictive signal.  The switch indicator is wired into the signal circuits. 

Assuming you are talking about a hand throw circuit in "dark" PTC territory, there is no indication back to the dispatcher (other than described above).  The switch will be wired into a local communication node that will communicate with the trains and PTC system by radio. 

[faraway]

Thanks a lot for all your explanations. I think Dave hit the nail and that explains why I never find any communication equipment at hand thrown switches in mainlines. The little box is wired to the local control circuits. CSX is in the process to use satellite communication (not for hand thrown switches :-) ). The dish antennas are shown on several photos.